1. Field of the Invention
The present invention relates to the field of generating electricity. More specifically, the present invention relates to the field of generating electricity and hydrogen with coal.
2. Description of the Related Art
The related art discloses electricity generating systems that produce syngas from coal and generate electricity from the syngas using a turbine and a solid oxide fuel cell. Under the appropriate conditions, these systems produce very low emissions of sulfur oxides ("SOx"), nitrogen oxides ("NOx"), alkalies, and particulates. The related art also discloses generating electricity from nuclear power which has clean emissions, but comes with the concerns of producing the nuclear power source and generating nuclear waste.
With both of the coal and nuclear sources of electricity, the cost per kilowatt hour is cheapest when the generating systems are operating at full capacity. However, the demand for electricity typically fluctuates in the course of a day, which leads to inefficient production of electricity during off-peak demand hours. The related art describes other processes integrated with the electrical generation plants to co-produce another product such that excess electrical generation capacity during off-peak demand hours is used in the co-production process.
The related art describes a nuclear power plant operating at full capacity by co-producing hydrogen. The nuclear power plant is integrated with an electrolysis plant that generates hydrogen from water by electrolysis. The integrated nuclear power plant/electrolysis plant system produces electricity on demand while it co-produces hydrogen using the nuclear power plant's excess capacity during off-peak demand hours. This results in a minimized cost of electricity and hydrogen.
Hydrogen is a beneficial co-product for its uses in a hydrogen-based economy, which uses hydrogen as a fuel, a chemical feedstock, and for other purposes. Hydrogen as a fuel is attractive because the combustion of hydrogen with oxygen to produce electricity and other sources of power has non-polluting water as an emission. The prospect of generating electricity without creating polluting emissions without nuclear energy is in itself is an incentive to grow the hydrogen-based economy. Hydrogen is also useful in other processes, such as a chemical feedstock in fertilizer production or in the production of metal hydrides, which is a source of fuel that does not have the storage concerns of liquid or gaseous hydrogen.
Therefore, a need exists for using coal to generate electricity and co-produce hydrogen in an economically viable process with low emissions of pollutants.